The Wendelstein 7-X reactor design looks promising

December 14, 2016 | 02:28

The Wendelstein 7-X reactor design looks promising

A little over a year ago, the German experimental fusion reactor Wendelstein 7-X was commissioned and tested in operation in Greifswald. Unlike a tokamak reactor design where powerful superconducting magnets confine the hot, charged gas or plasma around a simple 2D donut path the Wendelstein 7-X is a ‘Stellarator’ where the magnets guide the plasma around the reactor in a twisty 3D path. Recent tests indicate...

A little over a year ago, the German experimental fusion reactor Wendelstein 7-X was commissioned and tested in operation in Greifswald. Unlike a tokamak reactor design where powerful superconducting magnets confine the hot, charged gas or plasma around a simple 2D donut path the Wendelstein 7-X is a ‘Stellarator’ where the magnets guide the plasma around the reactor in a twisty 3D path. Recent tests indicate that the generated magnetic fields will be capable of containing the nuclear reactions because they are much more precise than expected. It’s looking hopeful, at last, that power out from a fusion generator will be greater than power in!

The fusion reactor Wendelstein 7-X was built and is operated by the Max Planck Institute for Plasma Physics in Greifswald. Research is ongoing, but these initial field measurements were made by first launching an electron beam along the field lines. The cross-sectional shape of the entire magnetic surface was then revealed by photographing a fluorescent rod that was swept through the lines. The measurements indicated that the magnetic field is extremely accurate with an error of just 10 ppm. According to the report’s authors "this is an unprecedented accuracy, both in terms of the as-built engineering of a fusion device, as well as in the measurement of magnetic topology". As ever the team acknowledged years of plasma physics research still lay ahead and "the task has just begun."